Pump



E. G. OFELDT July 10, 1934.

PUMP

Original Filed April 29, 1931 2 Sheets-Sheet 2 Patented July 10, 1934 PATENT OFFICE PUMP Ernest G. Ofeldt, Nyack, N. Y.

Application April 29, 1931-, Serial No. 533,817 Renewed May 24, 1934 6 Claims.

This invention relates to improvements in pumps, and more especially to fuel pumps for use in transferring gasoline or the like from the supply tank of an automobile to the carburetor.

One of the salient objects of the invention is to furnish a fuel pump for this purpose, that will be actuated by the explosive impulses of the engine of the vehicle, and including means for automatically cutting off the passage of pulsating gases from the engine to the pump when the float tank of thecarburetor is filled.

Another object is to provide a pump of this kind of simple inexpensive construction, and one which will operate efiiciently for long periods of time without necessity for repairing.

A still further object is to provide such a pump in which substantially all of the'internal parts of the pump may be removed from one end thereof, whereby when the pump is vertically arranged beneath the hood of an automobile, for example, its internal parts are accessible for repair or replacement without removing the entire pump from the vehicle.

With the foregoing objects outlined and with other objects in view which will appear as the description proceeds, the invention consists in the novel features hereinafterdescribed in detail, illustrated in the accompanying drawings, and more particularly pointed out in the appended'claims.

' In the drawings,

Fig. 1 is a side elevation of an internal combustion engine provided with my improved pump.

Fig. 2 is a vertical sectional view of the pump partly in elevation.

' Fig. 3 is a top plan view of the same. Figs. 4, 5, 6 and Tare transverse sectionalviews taken respectively on the line 4-4, 5-5, 6-6 and '7'7 of Fig. 2.

Referring to the drawings, 8 designates the pump casing preferably a metal casting, which is provided at one side with an explosive gas inlet 9 that is connected to the combustion space of one of the engine cylinders by a tube 10. Pulsating gases from the engine, after passing through the pipe 10, travel past aball valve 11 which controls a gas inletpassageway I2 in the pump casing leading to a chamber l3,'in which there is a loose piston 14 that is urged in one direction by a spring 15 which is held in position byan adjusting cap16' that closes the top of the chamber and has an aperture 17 for the escape of the pulsating: gases which leak by the piston. The gasoline intake conduitof the pump is shown at 18, and it is connected to a pipe 19 that leads to the fuel reservoir or supply tank, not shown.

A piston rod 20 is detachably connected to the piston, as shown at 2'1, and at its lower end, as shown at 2-2, to the spider 23 of a hollow piston 24. The latter piston has an intake 25 con trolled by a ball valve 26, the movement of which is limited by a cross pin 2'7 arranged within the hollow piston. The latter recipro'cates in a pump cylinder or chamber '28 that communicates with the duct 18 by a port 29 controlled by a ball valve 30 that is limited in its movement by a pi'n31 which extends across the pump cylinder. The piston rod extends upwardlythrough the cap 16 and terminates in a handle 20} which may be employed in working the pump by hand.

A tubular guide 32 projects into the cy1inder28 and snugly engages andacts as a guide for the piston rod '20. The guide provided at its top with a flange or head 33 having a beveled annular surface '34 engagedby screws 35 which are employed to detachably hold the guide in position. The flange rests on an annular ledge 36 at the bottom of the chamber 13, and the fit 'of the parts is'su'ch that the're will be no leakage from the chamber 13 to'the cylinder 28 and vice versa. This makes it unnecessary to use a stufling box or packing at this point. 7

As the spider 23 has ports 37 extending therethrough, liquid fuel drawn into the hollow pistonwill travel through a lateral port 38 into a duct 39 that is connected by a pipe 40 to the float chamber of a carburetor 41. v

For automatically, cuttingjofi the flow of pulsating gases to the pump and for preventing suction strokes of the engine from withdrawing gas through the passageway 12, the ball valve 11 00 o'per'ates with a stem 42 which is guided in an offset portion of the pump casing and has a head 43 yieldingly pressed upward by a coiled spring 44. The head abuts against a diaphragm 45, the edge of which is held'to'its seat by a circularplate 46 having an aperture'47 to permit fluid above the plate to act on the diaphragm and force the stem down to the point where it will prevent the ball valve from rising. The plate 46'is held in place by any suitable means such as a coil spring 48 which in turn is held in position by a removable cap 49 which closes the chamber 50 in which the diaphragm is located. This chamber is in com munication with the pump outlet duct 39 by means of a passageway 51. 2

Before proceeding with a detail description of the operation of the pump, it may be explained how the various parts are readily removed from file the upper end of the casing 8. When the cap 49 is detached, the spring 48, plate 46, diaphragm 45, headed stem 42, spring 44 and ball valve 11 may be removed in the order named. Also, when the cap 16 is removed and the screws 35 are loosened, the spring 15, loose piston 14, piston rod 20, guide 32, hollow piston 24 with ball valve 26 may be removed in that order. Obviously, this facilitates repair and replacement of parts.

In operation, it is desired that pulsating gases be employed whenever it is necessary to refill the float chamber of the carburetor 41, but it is undesirable to withdraw any fluid through the pipe 10 into the engine. Consequently, the Valve 11 allows pulsating gases from the engine totravel through the passageway 12, but immediately cuts off the flow in case there is any suction tendency in the tube 10. These pulsating gases will enter the chamber 13 and lift the piston 14, with the result that the hollow piston 24 will rise and gasoline will be drawn into the cylinder 28, past the valve 30. Then, when the expansive forces of these gases ceases, the spring 15 will force the piston 14 downwardly, while the pulsation gases flow upwardly along the periphery of the piston 14 and discharge at 17 into the atmosphere. As the piston 14 moves downwardly, the gasoline trapped in the cylinder 28 will flow upwardly past the valve 26 into the hollow cylinder 24, while the valve 30 remains seated. Then, as pulsating gases again raise the hollow piston 14, the gasoline from the interior of the hollow piston will pass through 38, 39 and 40 to the float chamber of the carburetor. As soon as the usual float controlled valve of the carburetor cuts off flow through the pipe 40, the fuel pump will travel through the passageway 51 into the chamber 50, and then through the instrumentality of the port 47, will exert its force on the diaphragm so that the latter will overcome the force of the spring 44 and will force the stem 42 downwardly until the valve 11 is seated. Therefore, whenever the float operated valve of the carburetor is closed, due to the rising of the float, the pump will be automatically stopped, and consequently, the

pump only operates when it is necessary to replenish the supply of gasoline in the carburetor float chamber.

While I have disclosed what I now consider to be a preferred embodiment of the invention in such manner that the same may be readily understood by those skilled in the art, I am aware that changes may be made in the details disclosed, without departing from the spirit of the invention, as expressed in the claims.

What I claim and desire to secure by Letters Patent is:

l. A pump of the character described, comprising a casing having a liquid inlet and a liquid outlet, segregated chambers in the casing, a hollow valved piston arranged in one of said chambers, the last mentioned chamber communicating with said inlet and outlet, a second piston arranged in the other one of said chambers, a pulsating gas inlet for the last mentioned chamber, a gas outlet for the last mentioned chamber, the second piston being of less diameter than its chamber to permit said gas to pass by the second piston and escape through the gas outlet, a spring for moving the second piston in one direction, means connecting the pistons for causing them to move in unison, and means actuated by the pumped liquid for closing said gas inlet.

2. A pump of the character described, comprising a casing having a liquid inlet and a liquid outlet, segregated chambers in the casing, a hollow valved piston arranged in one of said chambers, the last mentioned chamber communicating with said inlet and outlet, a second piston arranged in the other one of said chambers, a pulsating gas inlet for the last mentioned chamber, a gas outlet for the last mentioned chamber, the second piston being of less diameter than its chamber to permit said gas to pass by the second piston and escape through the gas outlet, a spring for moving the second piston in one direction, means connecting the pistons for causing them to move in unison, means actuated by the pumped liquid for closing said gas inlet, the last mentioned means including a compartment in the casing, a movable partition separating the compartment into first and second chambers, a passageway placing the first chamber of the compartment in communication with the outlet of the pump to permit the pumped fluid to exert its pressure on said movable partition, a'valve in the gas inlet, a stem engageable with said last mentioned valve and bearing against the movable partition, and yielding means normally holding the stem in such position as not to interfere with the opening of the valve.

3. In a pump of the character described, a gas passageway, a ball valve for controlling the flow of gas through said passageway, a compartment, a removable cover for said compartment, a partition in the compartment dividing the same into segregated first and second chambers, a liquid inlet for the first chamber, means in the first chamber for securing an edge of the movable partition, a stem in the second chamber having a head bearing against the movable partition at one end and engageable with the ball valve at its opposite end, a spring in the second chamber for normally holding the stem in such position as not to interfere with the movement of the ball, said retainer, movable partition, stem, spring and ball being removable through one end of said compartment when the cover of the latter is removed.

4. In a pump of the character described, a casing having axially aligned chambers, a piston in one of said chambers, a gas inlet and a gas outlet for the last mentioned chamber, said piston being of less diameter than its chamber to permit said gas to pass by the piston and escape through the gas outlet, a removable cap for closing one end of the last mentioned chamber, a spring between the cap and piston for moving the piston in one direction, a valve controlled liquid inlet for the other one of said chambers, a liquid outlet for the last mentioned chamber, a hollow valved piston in the last mentioned chamber, and a piston rod connecting said pistons, said pistons and rod all being removable through the cap closed end of the first mentioned chamber.

5. In a pump of the character described, a casing having axially aligned chambers, a piston in one of said chambers, a gas inlet and a gas outlet for the last mentioned chambers, said piston being of less diameter than its chamber to permit said gas to pass by the piston and escape through the gas outlet, a removable cap for closing one end of the last mentioned chamber, a spring between the cap and piston for moving the piston in one direction, a valve controlled liquid inlet for the other one of said chambers, a liquid outlet for the last mentioned chamber, a hollow valved piston in the last mentioned chamber, a piston rod connecting said pistons, and a guide for the piston rod segregating one chamber from the other.

a hollow valved piston in the last mentioned chamber, a piston rod connecting said pistons, and a guide for the piston rod segregating one chamber from the other, said spring, pistons, piston rod and guide being removable as a unit through one end of the casing when said cap is detached without disturbing the liquid inlet or the liquid outlet.

ERNEST G. OFELDT. 

